1. Field of the Invention
The present invention concerns the use of an extract from the leaves of Olea Europea (commonly called olive tree), as an antiradical, particularly in the cosmetic and alimentary fields.
2. Prior Art
The use of antioxidant substances, apt to prevent the forming of free radicals, is rather widespread both in the alimentary and in the cosmetic fields.
In the alimentary field, the oxidizing action is what causes the food to deteriorate. It is hence frequent to add into foods antiradicals for alimentary use, such as acetylsalicylic acid and its esters, or 1-ascorbic acid, which develop an antioxidant action.
In the cosmetic field, the antiradicalic substances are above all used for sun protection creams. In fact, the ultraviolet irradiation causes the forming of free radicals which determine a sort of skin ageing and, after a prolonged exposure, may even lead to damages of neoplastic nature.
The extract from the leaves of Olea Europea, already known since quite a long time, consists of an extremely complex mixture of orcanic components: most of them have not yet been identified. Among the components which have been identified, the main ones are oleoeuropeine and verbacoside. These two bitter glucosides are cited in literature and, precisely, in the xe2x80x9cGazzetta Chimica Italianaxe2x80x9d (1960xe2x80x94Vol. 90, page 1449) by L. Panizzi, M. L. Scarpati and E. G. Oriente, and in the xe2x80x9cJournal of Food Sciencexe2x80x9d (1993xe2x80x94Vol. 58, page 347) by M. Brenes, M. C. Duran and A. Garrido. Particularly oleoeuropeine is known as an antimicrobic substance, as resulting from the xe2x80x9cJournal of Applied Bacteriologyxe2x80x9d (1970xe2x80x94Vol. 33, page 72 and 1972xe2x80x94Vol. 35, page 559) by B. Juven and Y. Hems.
It has now been found that the extract from the leaves of Olea Europea, which contains more than 7% of oleoeuropeine, has considerable preserving properties. Such properties derive, not only from the known antimicrobic action cited heretofore, but also from a considerable antiradicalic actionxe2x80x94never evidenced up-to-date and, as a matter of fact, even unexpectedxe2x80x94which said extract has been found to develop.
The present invention has been conceived on the basis of said principle and actually concerns the use of an extract from the leaves of Olea Europea as an antiradical.
Said antiradicalic action provides great advantages in the preparing of cosmetics or foods.
In the cosmetic field, said extract finds its ideal use especially in sun protection creams.
In the alimentary field, said extract is mainly used for preparing dietetic products.
Preferably, said extract is added to the cosmetic or alimentary preparation in a concentration not exceeding 0.5% by weight.
The extract is prepared by dipping the leaves into water, and subjecting the infusion to ultrasounds, so as to accelerate the extraction. This allows to obtain an extract containing at least 7% by weight of oleoeuropeine. It is deemed that the antiradicalic action is partly produced by oleoeuropeine and partly by other substances synergistically acting therewith.
The extract thus obtained is added to the cosmetic or alimentary preparation in a concentration not exceeding 0.5% by weight, and then mixed therewith in any known manner.
In the cosmetic field, the action of the extract according to the present invention develops in the cosmetic product to which it is added as well as on the tissues on which said product is applied. It is particularly helpful in various types of cosmetic creams, and even more helpful in the case of sun protection creams. Such products bring the extract in contact with the skin and, in the case of certain preparations, they cause it to penetrate into the inner skin layers. In all such cases, the active substances contained in the extract from the leaves of Olea Europea stop the forming, in the tissues, of the free radicals determined by the action of ultraviolet irradiationxe2x80x94whether it be of natural origin, or artificially producedxe2x80x94so as to protect the skin from a premature ageing and from any possible phenomena of the neoplastic type. Moreover, as mentioned above, said extract also acts onto the components of the cosmetic preparation, preserving it from decay due to radicalic oxidation and considerably lengthening its life. As can be easily understood, this type of action is particularly appreciated and effective in the case of sun protection creams, which are used in conditions of highly strong UV rays, whereby the forming of free radicals is very likely to occur.
In the alimentary field, the extract is usedxe2x80x94according to the inventionxe2x80x94to delay the deterioration of the most perishable foodstuffs, for example long-life fruit juices or other soft drinks, jams and tinned fruits and vegetables, sacked meats and sausages, and particularly for the preparing of dietetic products.
According to the present invention, the use in the alimentary field is possible in that the extract contains sugars and agliconic derivatives, all of which are edible. Also in this case it, is not necessary to exceed a concentration of 0.5% by weight, seen that the extract develops a synergistic action with the antiradicalic substances usually soluble in the lipids, such as tocopherols. It is however advisable to proportion each time the concentration according to the particular food being preserved. The antiradicalic action develops both directly and indirectly, through a protective action on the tocopherols.
Since the antiradicalic action is mostly developed by the agliconic components, it is totally independent from the presence of enzymes. It may, on the contrary, develop both on the hydrosoluble and on the liposoluble substances, seen that aglicone is liposoluble: this allows to use the extract according to the present invention also in the hot-prepared alimentary products. The water-solubility of the extract of Olea Europea is remarkably higher than the effective dose; though being very low in the lipids, the solubility is however already sufficient to give an adequate protection to the alimentary substances also in the lipidic phase.